Willow Creek, Montana has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 30.9 °F (low) to 58 °F (high). Annual precipitation averages 11.3 Inches. Willow Creek is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 13.7 °F | 34.7 °F | 0.35 in. |
| February | 16.4 °F | 38.7 °F | 0.34 in. |
| March | 22.9 °F | 47.9 °F | 0.67 in. |
| April | 29.9 °F | 55.7 °F | 1.37 in. |
| May | 38.3 °F | 64.9 °F | 1.85 in. |
| June | 45.1 °F | 73.6 °F | 2.15 in. |
| July | 50.3 °F | 85.2 °F | 0.99 in. |
| August | 48.1 °F | 84.5 °F | 0.86 in. |
| September | 40.6 °F | 73.6 °F | 0.94 in. |
| October | 30.7 °F | 58.7 °F | 0.74 in. |
| November | 21.1 °F | 44.1 °F | 0.54 in. |
| December | 13.8 °F | 34.3 °F | 0.48 in. |
| Annual | 30.9 °F | 58 °F | 11.28 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |